Answer:
12.5 months
Explanation:
Let x be the number of months
Let f(n) be the money saved by person n
we know that f(J)=300+20m
we also know that f(T)=400+12m
we want f(J)=f(T) so we have 300+20m=400+12m. solving we get 8m=100 and so m=12.5. Thus in 12.5 months they will have the same amount.